[Samsung Galaxy Nexus] sergeroyal:
THIS IS NOT MY WORK!! I AM JUST SHARING THE INSTRUSTIONS!!

Instructions for flashing a phone or tablet device with Ubuntu:

The Ubuntu Touch Developer Preview is intended to be used for development and evaluation purposes only. It does not provide all of the features and services of a retail phone and cannot replace your current handset. This preview is the first release of a very new and unfinished version of Ubuntu and it will evolve quickly. If you want to install this release, please follow the guide provided, which details the available features and how to navigate the user experience.

This process will delete all data from the device. Restoring Android will not restore this data.

What to expect after flashing

Shell and core applications

Connection to the GSM network (on Galaxy Nexus and Nexus 4)

Phone calls and SMS (on Galaxy Nexus and Nexus 4)

Networking via Wifi

Functional camera (front and back)

Device accessible through the Android Developer Bridge tool (adb)

Supported devices and codenames

Device

Galaxy Nexus

maguro

takju or yakju

Nexus 4

mako

occam

Nexus 7

grouper

nakasi or nakasig

Nexus 10

manta

mantaray

Flashing the device

Step 1 - Desktop Setup

The following steps are required on your desktop system that you'll need in order to flash and communicate with the device.

Setup the Touch Developer Preview Tools PPA

The PPA has the tools and dependencies to support Precise, Quantal and Raring. Add the Ubuntu Touch PPA by adding the following custom source list entry to your /etc/apt/sources.list file.

sudo add-apt-repository ppa: phablet-team/tools

Then do the following:

sudo apt-get update

sudo apt-get install phablet-tools android-tools-adb android-tools-fastboot

Step 2 - Device unlock

If the device is already unlocked, skip to Step 3. These steps will wipe all personal data from the device.

With the device powered off, power on the device by holding the Power button + volume up + volume down.

The device will boot into the bootloader.

Plug the device into the computer via the USB cable.

On your computer, press Ctrl+Alt+T to start a terminal. Type sudo fastboot oem unlock, followed by Enter

On the device screen, accept the terms of unlocking.

Boot the device by pressing the power button (pointed by an arrow with Start on the screen).

Step 3 - Initial Device Setup

Follow these initial steps on your device:

1- If not booted, boot the device into Android

2- Enable USB debugging on the device

on Ice Cream Sandwich (version 4.0) go to Settings and turn on USB Debugging (Settings > System > Developer options > USB debugging).

on Jelly Bean (versions 4.1 and 4.2) you need to enter Settings, About [Phone|Tablet] and tap the Build number 7 times to see the Developer Options, activate USB Debugging via Settings > Developer options > USB debugging.

on 4.2.2 you will need to accept a host key on the device, if you already had adb installed, do the following

On the workstation-> adb kill-server; adb start-server

3- Plug the device into the computer via the USB cable.

Depending on the installed Android version, a popup will show up on the device with the host key that needs to be accepted for the device to communicate with the workstation.

4- Save the version of the current image on the device, if on Android, to use as a reference to revert back to. The version can be found by going to Settings > About Phone > Build Number.

Step 4 - Deploying Image to Device

To install the Ubuntu Touch Developer Preview on your device, you will need to execute the command below. Please note, this will wipe the contents of the device so ensure you have made a back-up. To install and get updates, run the following command:

phablet-flash -b

The -b performs a full bootstrap on the device. If the device is already unlocked it will carry on. If you have already bootstrapped once and want to install a daily just do:

phablet-flash

This will deploy the latest build onto your device. Your device should reboot into the Ubuntu Unity shell.

Note: the files are saved in Downloads/phablet-flash.

Restoring Android

The Ubuntu Touch Preview image is not for everyone and may not suit your current needs (yet). If you wish to roll back to an Android factory image, follow these steps:

1- Recall the version that was installed before flashing.

2- Download the factory image corresponding to your device's model and version (initial table has links).

3- Ensure the device is connected and powered on.

4- Extract the downloaded file and chdir into the extracted directory.

5- un adb reboot-bootloader

6- run ./flash-all.sh (use sudo if lack of permissions on the workstation don't allow you to talk to the device).

Your device should boot into Android after the process is finished.

Source: https://wiki.ubuntu.com/Touch/Install#Instructions_for_flashing_a_phone_or_tablet_device_with_Ubuntu